select 'oracle' type_name,       ( select instance_name from v$instance ) dbms_name,       owner constraint_catalog,       owner constraint_schema,       constraint_name,       index_owner unique_constraint_catalog,       index_owner unique_constraint_schema,      constraint_name unique_constraint_name,      NULL match_option,      NULL update_rule,      delete_rule  from dba_constraints a  where owner is not null   and constraint_type in ('R','?')
